Traditionally, telephony communications within the United States were handled by the public switched telecommunications network (PSTN). The PSTN can be characterized as a network designed for voice communications, primarily on a circuit-switched basis, with full interconnection among individual networks. The PSTN network is largely analog at the local loop level, digital at the backbone level, and generally provisioned on a wireline, rather than a wireless, basis. The PSTN includes switches that route communications between end users. Circuit switches are the devices that establish connectivity between circuits through an internal switching matrix. Circuit switches set connections between circuits through the establishment of a talk path or transmission path. The connection and the associated bandwidth are provided temporarily, continuously, and exclusively for the duration of the session, or call. While developed to support voice communications, circuit switches can support any form of information transfer (e.g., data and video communications).
In a traditional PSTN environment, circuit switches include central office (CO) exchanges, tandem exchanges, access tandem exchanges, and international gateway facilities. Central offices, also known as exchanges, provide local access services to end users via local loop connections within a relatively small area of geography known as an exchange area. In other words, the CO provides the ability for a subscriber within that neighborhood to connect to another subscriber within that neighborhood. Central offices, also known as end offices, reside at the terminal ends of the network. In other words, COs are the first point of entry into the PSTN and the last point of exit. They are also known as class 5 offices, the lowest class in the switching hierarchy. A class 5 telephone switch communicates with an analog telephone using the analog telephony signals in the well-known analog format. The class 5 telephone switch provides power to the telephone; detects off-hook status of the telephone and provides a dial tone in response; detects dual-tone multi-frequency signals from the caller and initiates a call in the network; plays a ringback tone to the caller when the far-end telephone is ringing; plays a busy tone to the caller when the far-end telephone is busy; provides ring current to the telephone on incoming calls; and provides traditional telephone services such as call waiting, call forwarding, caller ID, etc.
In an effort to increase the amount and speed of information transmitted across networks, the telecommunications industry is shifting toward broadband packet networks which are designed to carry a variety of services such as voice, data, and video. For example, asynchronous transfer mode (ATM) networks have been developed to provide broadband transport and switching capability between local area networks (LANs) and wide area networks (WANs). The Sprint ION network is a broadband network that is capable of delivering a variety of services such as voice, data, and video to an end user at a residential or business location. The Sprint ION network has a wide area IP/ATM or ATM backbone that is connected to a plurality of local loops via multiplexers. Each local loop carries ATM over ADSL (asymmetric digital subscriber line) traffic to an integrated service hub (ISH), which may be at either a residential or a business location.
An ISH is a hardware component that links business or residential user devices such as telephones and computers to the broadband, wide area network through a plurality of user interfaces and at least one network interface. A suitable ISH is described in U.S. Pat. No. 6,272,553 entitled “Multi-Services Communications Device,” issued on Aug. 7, 2001, which is incorporated by reference herein in its entirety. The network interface typically is a broadband network interface such as ADSL, T1, or HDSL-2. Examples of user interfaces include telephone interfaces such as plain old telephone system (POTS) ports (also referred to as jacks) for connecting telephones, fax machines, modems, and the like to the ISH; computer interfaces such as ethernet ports for connecting computers and local area networks to the ISH; and video ports such as RCA jacks for connecting video players, recorders, monitors, and the like to the ISH.
Each ISH is provided with an identification code known as a Media Access Control (MAC) ID that uniquely identifies a particular ISH. The MAC ID is a hardware identifier associated with the Network Interface Card (NIC) in each ISH. An ISH identifies itself to a configuration server by sending its MAC ID to the server. The server contains a database of configurations for all ISHs, including global and customer specific configuration parameters. Thus, each ISH can have its own unique configuration based on its MAC ID.
In providing telephony services over a broadband network, the ISH typically relays a signal between a user's telephone and a series of intermediate devices leading to the network. As used herein “telephone” generally refers to a device, a portion of which is typically handheld, for converting sound to electrical signals and vice-versa and further comprising a ringer that rings in response to a ring current, provided however that telephone should also be understood to include any device that responds to telephony signals such as a facsimile machine, modem, or computer. Telephones typically use the analog telephony format. Digital format telephones could also be used, with the understanding that the specific support circuitry in the ISH would change while providing equivalent functions (for example, detecting hook transitions).
A typical series of devices through which a signal might pass between a broadband network and a telephone is shown in FIG. 1. An incoming signal from a network 1 or the Internet 2 to a telephone 18 first passes through a service node 4, then through front end routers 6, an ATM switch 8, an ATM multiplexer (AMUX) 10, and a network edge device 12 such as a digital subscriber line access multiplexer (DSLAM). The signal then passes through connection 15, which is typically a metallic line (e.g., a twisted copper pair of wires) controlled by a local telephone company, also known as a Local Exchange Carrier or LEC, into a customer premises device 16 such as an ISH. The ISH 16 then sends the signal to the telephone 18.
A provider of broadband telephony services typically has control of all equipment and connections from the network 1 up to and including the DSLAM 12. Network monitoring devices installed in the network 1 and DSLAM 12 provide physical path verification of the connections to discover, diagnose, and locate problems occurring between the network 1 and DSLAM 12. If a loss of signal or other physical layer transmission error occurred between those two points, the service provider would be able to remotely pinpoint the location and nature of the problem. However, the monitoring devices cannot provide service layer visibility over the entire path from the network 1 to the telephone 18. The equipment and connections from LEC line 15 to the telephone 18 are not controlled by the service provider and therefore cannot always be monitored remotely. With existing technology, the provider typically cannot determine remotely whether a problem in the path from the LEC line 15 to the telephone 18 is located in the LEC line 15, the ISH 16, or the customer's telephone 18. A repair technician would have to be dispatched to locate such a problem. Dispatching a technician is expensive and can turn out to be unnecessary if the problem is discovered to be within the LEC line 15 or the customer's telephone 18 or is attributed to user error.